Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence for a display screen or portion thereof with transitional graphical user interface showing our new design;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof;

FIG. 4 is the design of FIG. 1 shown in an illustrative environment;

FIG. 5 is the design of FIG. 2 shown in an illustrative environment; and,

FIG. 6 is the design of FIG. 3 shown in an illustrative environment.

The appearance of the graphical user interface transitions sequentially between the images shown in FIGS. 1-3, and FIGS. 4-6 respectively.

The process or period in which one image transitions to another forms no part of the claimed design. The difference in shading indicates a contrast of appearance and does not depict any particular color, texture, or material. The broken lines depicting the display screen, remainder of the graphical user interface, and illustrative environment show features that form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described. 